Updates to software are usually done for the better, but sometimes it results in changes that are less than ideal. This is what seems to be the case right now for T-Mobile iPhone users who are discovering that after the update to iOS 11.3, their phones are starting to prioritize cellular calls over WiFi calling.

Users are reporting that after iOS 11.3 and the Carrier Bundle 32.0, their iPhones won’t use WiFi calling unless their cellular signal drops to a very low point, which is around...